Tapered Fluidic Diode For Use As An Autonomous Inflow Control Device AICD

ABSTRACT

A system for providing autonomous flow control of a fluid from a wellbore to an interior of a tubing string by using a variable flow resistance system. The system can include a body, with a chamber that can be configured to induce rotational flow in a fluid that flows through the chamber. The chamber can include an inlet for fluid entering the chamber and an outlet for fluid exiting the chamber. A cross-sectional area of the chamber can be reduced along a central axis of the chamber toward the outlet, with the cross-sectional area being perpendicular to a central axis. A well screen assembly may utilize one or more of the variable flow resistance systems to provide a determined flow resistance and/or flow rate of the fluid through the screen assembly.

TECHNICAL FIELD

The present disclosure generally relates to systems and methods forregulating fluid flow, particularly within a subterranean formation,and, more specifically, to rotational motion-inducing variable flowresistance systems. These variable flow resistance systems canautonomously vary a resistance to flow of a fluid through the systemsbased on one or more characteristics of the fluid.

BACKGROUND

It can be beneficial to regulate the flow of formation fluids within awellbore penetrating a subterranean formation. A variety of reasons orpurposes can necessitate such regulation including, for example,prevention of water and/or gas coning, minimizing water and/or gasproduction, minimizing sand production, maximizing oil production,balancing production from various subterranean zones, equalizingpressure among various subterranean zones, and/or the like.

Likewise, it can also be beneficial to regulate the flow of injectionfluids such as, for example, water, steam or gas, within a wellborepenetrating a subterranean formation. Regulation of the flow ofinjection fluids can be particularly useful, for example, to control thedistribution of the injection fluid within various subterranean zonesand/or to prevent the introduction of injection fluid into currentlyproducing zones.

Therefore, it will be readily appreciated that improvements in the artsof fluid inflow control devices are continually needed.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the present disclosure will be understood morefully from the detailed description given below and from theaccompanying drawings of various embodiments of the disclosure. In thedrawings, like reference numbers may indicate identical or functionallysimilar elements. Embodiments are described in detail hereinafter withreference to the accompanying figures, in which:

FIG. 1 is a representative partial cross-sectional view of a wellbore inwhich the variable flow resistance systems of the present disclosure canbe used, according to one or more example embodiments;

FIGS. 2A-2B are representative partial cross-sectional views of a wellscreen in which the variable flow resistance systems of the presentdisclosure can be used, according to one or more example embodiments;

FIGS. 3A-3C are representative partial cross-sectional views of aninflow control portion of the well screen in which the variable flowresistance systems of the present disclosure can be used, according toone or more example embodiments;

FIG. 4 is a representative unrolled view of a base pipe of the wellscreen shown in FIGS. 2A-2B;

FIGS. 5A-12 are representative cross-sectional side views of exampleconfigurations of the variable flow resistance system; and

FIGS. 13A-15B are representative cross-sectional top views of exampleconfigurations of the variable flow resistance system.

DETAILED DESCRIPTION OF THE DISCLOSURE

The disclosure may repeat reference numerals and/or letters in thevarious examples or Figures. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.Further, spatially relative terms, such as beneath, below, lower, above,upper, uphole, downhole, upstream, downstream, and the like, may be usedherein for ease of description to describe one element or feature'srelationship to another element(s) or feature(s) as illustrated, theupward direction being toward the top of the corresponding figure andthe downward direction being toward the bottom of the correspondingfigure, the uphole direction being toward the surface of the wellbore,the downhole direction being toward the toe of the wellbore. Unlessotherwise stated, the spatially relative terms are intended to encompassdifferent orientations of the apparatus in use or operation in additionto the orientation depicted in the Figures. For example, if an apparatusin the Figures is turned over, elements described as being “below” or“beneath” other elements or features would then be oriented “above” theother elements or features. Thus, the exemplary term “below” canencompass both an orientation of above and below. The apparatus may beotherwise oriented (rotated 90 degrees or at other orientations) and thespatially relative descriptors used herein may likewise be interpretedaccordingly.

Moreover even though a Figure may depict a horizontal wellbore or avertical wellbore, unless indicated otherwise, it should be understoodby those skilled in the art that the apparatus according to the presentdisclosure is equally well suited for use in wellbores having otherorientations including vertical wellbores, slanted wellbores,multilateral wellbores or the like. Likewise, unless otherwise noted,even though a Figure may depict an offshore operation, it should beunderstood by those skilled in the art that the method and/or systemaccording to the present disclosure is equally well suited for use inonshore operations and vice-versa. Further, unless otherwise noted, eventhough a Figure may depict a cased hole, it should be understood bythose skilled in the art that the method and/or system according to thepresent disclosure is equally well suited for use in open holeoperations.

As used herein, the words “comprise,” “have,” “include,” and allgrammatical variations thereof are each intended to have an open,non-limiting meaning that does not exclude additional elements or steps.While compositions and methods are described in terms of “comprising,”“containing,” or “including” various components or steps, thecompositions and methods also can “consist essentially of” or “consistof” the various components and steps. It should also be understood that,as used herein, “first,” “second,” and “third,” are assigned arbitrarilyand are merely intended to differentiate between two or more objects,etc., as the case may be, and does not indicate any sequence.Furthermore, it is to be understood that the mere use of the word“first” does not require that there be any “second,” and the mere use ofthe word “second” does not require that there be any “first” or “third,”etc.

The terms in the claims have their plain, ordinary meaning unlessotherwise explicitly and clearly defined by the patentee. Moreover, theindefinite articles “a” or “an,” as used in the claims, are definedherein to mean one or more than one of the element that it introduces.If there is any conflict in the usages of a word or term in thisspecification and one or more patent(s) or other documents that may beincorporated herein by reference, the definitions that are consistentwith this specification should be adopted.

Generally, this disclosure is directed to a system for autonomouslyregulating fluid flow, particularly within a subterranean formation,and, more specifically, to rotational motion-inducing variable flowresistance systems. A system can provide autonomous flow control of afluid flowing between a wellbore to an interior of a tubing string byusing the variable flow resistance system. The system can include abody, with a chamber that can be configured to induce rotational flow ina fluid that flows through the chamber. The chamber can include an inletfor fluid entering the chamber and an outlet for fluid exiting thechamber. A cross-sectional area of the chamber can be reduced along acentral axis of the chamber toward the outlet, with the cross-sectionalarea being perpendicular to a central axis. Additionally, a well screenassembly may utilize one or more of the variable flow resistance systemsto provide a determined flow resistance and/or flow rate through thescreen assembly.

As discussed above, variable flow resistance systems that inducerotational motion within a fluid typically can incorporate a fluid exithole at the bottom of a chamber, where the location of the exit holefacilitates vortex-like rotational motion of the fluid. However, thislocation of the exit hole can make series connections between chambersproblematic if a greater degree of fluid flow regulation is needed thancan be provided by a single chamber.

The present disclosure describes variable flow resistance systems thathave chambers both with and without a fluid exit hole extending throughthe bottom of the chamber. The embodiments that do not have a fluid exithole extending through the bottom of the chamber, have a fluid outletlocated in a sidewall of the chamber. The primary advantage of chamberswith sidewall exits is that they can be efficiently coupled together inseries in a variable flow resistance system (e.g., in a substantiallyhorizontal arrangement) without having to conduct excessive verticalmovement of the fluid during transport between adjacent chambers. Asubstantially horizontal arrangement offered by the sidewall exitchambers can be particularly efficient in terms of space utilization,such that they can be readily used in confined regions, such as within awellbore penetrating a subterranean formation. Furthermore, theopportunity to connect multiple chambers in series in a variable flowresistance system can achieve greater fluid flow regulation than isattainable using a single chamber alone. If a series configuration isnot needed (e.g. one chamber can provide sufficient flow resistance),then the bottom hole exit can be used to advantage.

In some embodiments, variable flow resistance systems described hereincan comprise a chamber configured to induce rotational motion of a fluidflowing therethrough, a fluid inlet coupled to the chamber; and a fluidoutlet coupled to the chamber that allows the fluid to exit through asidewall or a bottom of the chamber.

In some embodiments, multiple chambers can be connected in series withone another in a variable flow resistance system. In some embodiments,variable flow resistance systems described herein can comprise aplurality of chambers that are connected in series fluid communicationwith one another, where each chamber has a fluid inlet and a fluidoutlet coupled thereto, and at least some of the chambers are configuredto induce rotational motion of a fluid flowing therethrough, and thefluid outlets of at least some of the chambers are configured to allowthe fluid to exit through a sidewall of the chamber, with other fluidoutlets configured to allow the fluid to exit through a bottom of thechamber.

When multiple chambers are connected in series in a variable flowresistance system, the chambers can all be the same in some embodiments,or at least some of the chambers can be different in other embodiments.In some embodiments, all of the chambers can have a fluid outlet thatallows a fluid to exit through a sidewall of the chamber. In otherembodiments, chambers having a fluid outlet that allows a fluid to exitthrough a sidewall of the chamber can be used in combination withchambers that have a fluid outlet exiting through the bottom of thechamber. The choice of a particular combination of chambers may bedictated by operational needs that will be evident to one havingordinary skill in the art.

As used herein, the term “chamber” refers to an enclosed space having atleast one inlet and at least one outlet. As used herein, use of the term“chamber” makes no implication regarding the shape and/or dimensions ofthe chamber unless otherwise specified.

As used herein, the term “sidewall” refers to any surface of chamberextending between the chamber's top exterior surface and the chamber'sbottom exterior surface. As used herein, the term “exterior surface”refers to the outside surface of a chamber that is not in contact with afluid passing through the chamber. As used herein, the term “rotationalmotion” refers to motion that occurs around an axis.

In various embodiments, the variable flow resistance systems of thepresent disclosure can be used in a wellbore penetrating a subterraneanformation. FIG. 1 shows a partial cross-sectional schematic of thewellbore 12 in which the variable flow resistance systems 25 of thepresent disclosure can be used. As shown in FIG. 1, well system 10contains wellbore 12 having a generally vertical uncased section 14,extending from cased section 16, and a generally horizontal uncasedsection 18 extending through subterranean formation 20. Wellbore pipe 22extends through wellbore 12, where wellbore pipe 22 can be any fluidconduit that allows fluids to be transported to and from wellbore 12. Insome embodiments, wellbore pipe 22 can be a tubular string such as aproduction tubing string.

Multiple well screens 24, each in fluid flow communication with variableflow resistance systems 25, can be connected to wellbore pipe 22.Packers 26 can seal an annulus 28 defined by wellbore pipe 22 and theinterior surface of horizontal uncased section 18. Packers 26 canprovide zonal isolation of various subterranean zones penetrated bywellbore pipe 22, thereby allowing fluids 30 to be produced from orintroduced into some or all of the zones of subterranean formation 20.Well screens 24 can filter fluids 30 as they move toward the interior ofwellbore pipe 22. Each variable flow resistance system 25 can regulateaccess of fluids 30 to the interior of wellbore pipe 22 and/or restrictthe flow of certain types of fluids 30 based upon certaincharacteristics or physical properties thereof.

It should be understood that the variable flow resistance systemsdescribed herein are not limited to the implementation displayed in FIG.1, which has been presented merely for purposes of illustration and notlimitation. For example, the type of wellbore 12 in which the presentvariable flow resistance systems 25 can be used is not particularlylimited, and it is not necessary that wellbore 12 contain eithervertical uncased section 14 or horizontal uncased section 18.Furthermore, any section of wellbore 12 can be cased or uncased, andwellbore pipe 22 can be placed in any cased or uncased wellbore section.

Furthermore, it is not required that fluids 30 are solely produced fromsubterranean formation 20, since fluids can be injected intosubterranean formation 20 and produced therefrom in some embodiments. Inaddition, the various elements coupled to wellbore pipe 22 that arepresented in FIG. 1 are all optional, and each may not necessarily beused in each subterranean zone, if at all. In some embodiments, however,the various elements coupled to wellbore pipe 22 can be duplicated ineach subterranean zone. Still further, zonal isolation using packers 26need not necessarily be performed, or other types of zonal isolationtechniques familiar to one having ordinary skill in the art can be used.

These variable flow resistance systems 25 can restrict the passage ofsome fluids more than others based upon one or more physical propertydifferences between the fluids. Illustrative physical properties of afluid that can determine its rate of passage through a variable flowresistance system can include, for example, viscosity, velocity anddensity. Depending on the type, composition and physical properties of afluid or fluid mixture whose passage is to be restricted, variable flowresistance systems 25 can be configured such that higher ratios of adesired fluid to an undesired fluid can flow through a flow pathwaycontaining the variable flow resistance system 25.

Rotational motion can be particularly effective for variably restrictingfluid flow within a variable flow resistance system. In variable flowresistance systems 25 capable of inducing rotational motion, a fluidcomposition may enter a chamber 50 within the variable flow resistancesystem 25 in such a way that an undesired component of the fluidcomposition undergoes greater rotational motion than does a desiredcomponent of the fluid composition. As a result, the undesired componenttraverses a longer flow pathway than does the desired component, and theundesired component's residence time within the variable flow resistancesystem 25 can be increased. The variable flow resistance system can beconfigured such that fluid exiting the variable flow resistance system25 is discharged through one or more holes in the bottom and/or sides ofthe chamber 50. The fluid 30 can be a fluid composition that containsboth desired and undesired components, or the fluid 30 can be either adesired or undesired fluid, without containing components of the othertype fluid. The viscosity, velocity and/or density of the fluid 30 (orcomponents in the fluid 30) can be used by the variable flow resistancesystem 25 (may also be known as Autonomous Inflow Control Devices AICDs)to autonomously restrict undesired fluids or fluid components more thandesired fluids or fluid components without moving parts in the variableflow resistance system 25 (other than the fluid 30 or material containedwithin the fluid 30 as it flows through the system 25).

In various non-limiting embodiments, the present variable flowresistance systems 25 can be used to prevent water coning or gas coningfrom subterranean formation 20. In some embodiments, the presentvariable flow resistance systems 25 can be used to equalize pressure andbalance production between heel 13 and toe 11 of wellbore 12. In otherembodiments, the present variable flow resistance systems 25 can be usedto minimize the production of undesired fluids and to maximize theproduction of desired fluids. It should also be understood that thepresent variable flow resistance systems 25 can be used for injectionoperations as well to accomplish similar advantages to those notedabove.

Whether a fluid is a desired fluid or an undesired fluid will usually bedetermined by the nature of the subterranean operation being conducted.For example, if the goal of a subterranean operation is to produce oilbut not natural gas or water, the oil can be considered a desired fluidand the natural gas and water can be considered undesired fluids. Inother cases, natural gas can be a desired fluid, and water can be anundesired fluid. It should be noted that at downhole temperatures andpressures, natural gas can be at least partially liquefied, and in thedisclosure presented herein, the term “natural gas” or more simply “gas”will refer to a hydrocarbon gas (e.g., methane) that is ordinarily inthe gas phase at atmospheric pressure and room temperature.

In general, the variable flow resistance systems 25 described herein canbe used in any subterranean operation in which there is a need toregulate the flow of fluids to or from the interior of a wellbore pipe22. Reasons why one of ordinary skill in the art might wish to regulatethe flow of fluids can include, for example, to prevent or minimizewater and/or gas coning, to prevent or minimize water and/or gasproduction, to prevent or minimize sand production, to maximize oilproduction, to better balance production from various subterraneanzones, to better equalize pressure among various subterranean zones,and/or the like.

In particular, the variable flow resistance systems 25 described hereincan be used during production or injection operations within asubterranean formation in some embodiments. In some embodiments, methodsfor using the variable flow resistance systems 25 of the presentdisclosure can comprise: installing a wellbore pipe 22 in an uncompletedwellbore 12, wherein the wellbore pipe 22 comprises at least onevariable flow resistance system 25 that is in fluid communication withthe interior of the wellbore pipe 22. In such embodiments, each variableflow resistance system 25 can comprise a plurality of chambers 50 thatare connected in series fluid communication with one another, where eachchamber 50 has a fluid inlet and a fluid outlet coupled thereto, and atleast some of the chambers 50 are configured to induce rotational motionof a fluid flowing therethrough and the fluid outlets of at least someof the chambers 50 are configured to allow the fluid to exit through asidewall and/or a bottom of the chamber 50.

In some embodiments, the methods can further comprise allowing aformation fluid 30 to flow through at least some of the variable flowresistance systems 25 and into the interior of the wellbore pipe 22. Insome embodiments, the methods can further comprise producing theformation fluid 30 from the wellbore pipe 22.

In some embodiments, the present variable flow resistance systems 25 canbe used in injection operations. For example, the variable flowresistance systems 25 can be used to control the introduction of varioustypes of treatment fluids into a subterranean formation. In injectionoperations, fluids that can be injected can include, for example, steam,liquefied gases and water. The variable flow resistance systems 25 canbe used to compensate for heel-to-toe pressure variations orpermeability variations within the subterranean formation.

In some embodiments, the wellbore 12 can comprise a horizontal wellbore.In other embodiments, the wellbore 12 can comprise a vertical wellbore.In some embodiments, the wellbore can comprise a plurality of intervals,where there is at least one variable flow resistance system 25 locatedwithin each interval.

The present variable flow resistance systems 25 can comprise at leastone chamber 50 that has a fluid outlet 82. Some illustrative variableflow resistance systems 25 are described in more detail hereinbelow withreference to the drawings. Other implementations, orientations,arrangements and combinations of the features described hereinbelow andpresented in the drawings are possible, and given the benefit of thepresent disclosure, it will be within the capabilities of one havingordinary skill in the art to combine these features. Additionally, allfeatures of the variable flow resistance systems 25 disclosed in someembodiments can be used in the other embodiments disclosed herein.

In some embodiments, the chambers 50 of the present disclosure cancontain various flow-inducing structures 90, 92 that induce rotationalmotion to a fluid flowing therethrough. In some embodiments, theflow-inducing structures can be formed as vanes or recesses on or withinthe interior surfaces 76, 77, 78, 79 (FIGS. 5A-12) of the chamber 50.Any number of flow-inducing and/or flow-restricting structures can beused within the chambers to impart a desired degree of flow resistanceto a fluid 30 passing therethrough.

Furthermore, in some embodiments, the design of the chambers 50 can besuch that only fluids with certain physical properties can undergo adesired degree of rotational motion within the chamber 50. That is, insome embodiments, the design of the chambers 50 can be configured totake advantage of a fluid's physical properties such that at least onephysical property dictates the fluid's rate of passage through thechamber. Specifically, fluids having certain physical properties (e.g.,viscosity, velocity and/or density) can be induced to undergo greaterrotational motion when passing through the chamber, thereby increasingtheir transit time relative to fluids lacking that physical property.For example, in some embodiments, the chamber 50 can be configured toinduce increasing rotational motion of a fluid with decreasing fluidviscosity. Consequently, in such embodiments, a fluid having a greaterviscosity (e.g., oil) can undergo less rotational motion when passingthrough the chamber than does a fluid having a lower viscosity (e.g.,gas or water), and the high viscosity fluid can have its transit timethrough a flow pathway affected to a much lesser degree than does thelow viscosity fluid.

Various types of fluid outlets 82 are compatible with the variable flowresistance systems 25 described herein. In some embodiments, the fluidoutlet 82 can comprise a channel within the chamber 50 that extends fromthe top or bottom interior surface of the chamber 50 and a sidewalland/or bottom of the chamber. In some embodiments, the fluid outlet 82can comprise a cone-shaped fluid outlet 82, a hole in the sidewalland/or bottom of the chamber 50, at least one groove or slit within thesidewall of the chamber. Other types of fluid outlets 82 can include,for example, curved pathways, helical pathways, pathways withdirectional changes, and segmented pathways with diameter variations.Combinations of different fluid outlet 82 types are also possible.

FIG. 2A shows a partial cross-sectional view of a well screen assembly24 that can be used in the well system 10. The screen assembly 24 caninclude many different configurations of ends 44, 46, filter layer (e.g.wire wraps 42), base pipe 40, and variable flow resistance systems 25,as well as more conventional inflow control devices. In the exampleshown in FIG. 2A, triangle-cross-section wire 42 can be wrapped aroundthe base pipe 40 and supported away from the base pipe 40 by supports(not shown), thereby forming a filter layer 51 consisting of spaces 53between adjacent wire 42 sections and a drainage layer 52 defined by thespace between the wires 42 and the exterior of the base pipe 40. Fluid30 can flow through the spaces 53 in the filter layer 51, through thedrainage layer 52 (e.g. fluid flow 32), and through one or more variableflow resistance systems 25 to join the fluid flow 36 in the flow passage48 of the screen assembly 24. The end 44 can form an annular region 43between the base pipe 40 and the end 44 that can contain one or morevariable flow resistance systems 25 for variably restricting the flow offluid through the screen assembly 24. Fluid flow 32 from the drainagelayer 52 can enter a variable flow resistance system 25 as fluid flow 33through an inlet 80 (see FIG. 3A), experience a variable rotational flow35, and exit through an outlet 82 (see FIG. 3A) as fluid flow 34, whichcan join the fluid flow 36 in flow passage 48. The variable rotationalflow 35 can change depending on the characteristics of the fluid 30flowing through the screen assembly 24, thereby providing variations ina restriction to flow through the variable flow resistance (VFR) system25. Increased backpressure of the fluid flow 33 would increaserestriction to flow through the system 25, and a decreased backpressureof the fluid flow 33 would decrease restriction to flow through thesystem 25.

The screen assembly shown in FIG. 2B is very similar to FIG. 2A, exceptthat multiple variable flow resistance systems 25 are shown arranged inseries fluid communication with each other in the annular region 43,with the first VFR system 25 receiving fluid flow 33 at its input andoutputting fluid flow 34 through an outlet 82 in a sidewall of thechamber 50 of the VFR system 25. Fluid flow 34 from the first VFR system25 outlet 82 can flow to an inlet 80 of a second VFR system 25 via fluidflow 38 and exit the second VFR system 25 as fluid flow 34. The fluid 30flowing through each of the VFR systems 25 may experience rotationalflow 35 in each of the chambers 50, thereby producing a largerresistance to flow of the fluid 30.

FIGS. 3A-3C show various configurations of the end 44 and annular region43 of the screen assembly 24. FIG. 3A shows a portion of the base pipe40 adjacent the end 44 with openings 56. It should be understood thatmultiple openings 56 can be positioned circumferentially around the basepipe 40, yet only two are shown in the example of FIG. 3A. The screenassembly 24 can be configured at the surface to provide the desiredamount of VFR systems 25 installed in the available openings 56, withany remaining openings not receiving a VFR system 25 to be plugged by aplug 54, thereby forcing fluid flowing through the screen assembly 24 toflow through the VFR systems 25. The end 44 may also include an annularsupport 45 with multiple openings to allow fluid flow 32 to enter theannular region 43 of the end 44 while supporting the portion of the end44 that is adjacent to the wire wraps 42. It should be understood thatthis support 45 is not required, since the end 44 could be supported byVFR systems, other support structures, or may not require additionalsupport at all.

The single VFR system 25 shown in FIG. 3A has a single inlet 80 thatreceives fluid flow 33, a single outlet 82 that outputs fluid flow 34into the flow passage 48 where it can join fluid flow 36. The chamber 50can include interior surfaces 76, 77, and 78 as well as an interiorsurface 79 of the outlet 82. As fluid 30 enters the VFR system 25 asfluid flow 33, it interacts with the surfaces 76, 77 which can urge thefluid 30 to flow rotationally around the axis 60 of the VFR system 25,which in this configuration is in line with axis 62 of the chamber 50.As stated above, if the fluid 30 is undesired fluid, then the rotationalflow 35 can be increased, thereby increasing flow restriction throughthe VFR system 25, and reducing flow through the screen assembly 24.However, if the fluid 30 is a desired fluid, then the rotational flow 35can be minimized, thereby decreasing flow restriction through the VFRsystem 25, and increasing flow through the screen assembly 24. In thisexample the surface 77 is a cylindrical surface positioned at the top ofthe chamber 50 with the surface 76 being conically shaped. The inlet 80can direct the fluid flow 33 toward a surface 76, 77 and slightly awayfrom the axis 60, 62. It should be understood that these surfaces 76, 77can be smooth, rough, grooved, and/or slotted, and can contain recessesand/or protrusions to either encourage or discourage rotational flow 35in the fluid 30 that passes through the VFR system 25.

The end 44 and annular region 43 of the screen assembly 24 shown in FIG.3B is very similar to that shown in FIG. 3A, except that the plug 56 isreplaced with a second VFR system 25. The first VFR system 25 canreceive fluid 30 from the drainage layer 52 via fluid flow 32 and 33.Rotational flow 35 about axis 60 may be induced in the fluid 30 as ittravels through the first VFR system 25 and exits the outlet 82positioned in a sidewall of the first VFR system 25. As fluid flow 34exits the first VFR system 25, it is directed to the input 80 of thesecond VFR system 25 by fluid flow 38 which can be constrained in a tubeconnecting the two VFR systems 25, or constrained by a partition in theannular region 43 that forces fluid flow 38 to enter the second VFRsystem 25 as fluid flow 33. Rotational flow 35 about axis 60 may againbe induced in the fluid 30 as it travels through the second VFR system25 and exits into the flow passage 48 from the outlet 82 positioned in asidewall of the second VFR system 25. This configuration can provideadditional flow restriction to fluid 30 flowing through the screenassembly 24 than can be provided by a single VFR system 25.

However, if less flow restriction and more flow rate is desired, thenmultiple single (i.e. not-cascaded) VFR systems 25 can be installed inthe openings 56 in the base pipe 40 to allow more parallel paths for thefluid 30 to flow through the screen assembly. FIG. 3C shows such anexample configuration. FIG. 3C is very similar to FIGS. 3A and 3B,except that VFR systems 25 are installed in the desired number ofopenings 56 (only two shown), with each VFR system 25 receiving fluid 30from fluid flow 32 from the drainage layer 52, with a portion of thefluid flow 32 flowing around and/or over the first VFR system 25 toreach the second VFR system 25 in the annular region. Both VFR systems25 shown in the cross-section can receive a portion of the fluid 30 asinput fluid flow 33. Rotational flow 35 about axis 60 may be induced inthe portion of the fluid 30 that travels through the each VFR system 25and exits the outlet 82 positioned in a bottom of each VFR system 25.Fluid flow 34 from each VFR system 25 can enter the flow passage 48 andjoin fluid flow 36 that can flow to the surface.

FIG. 4 shows an example of a base pipe 40 of a screen assembly unrolledto illustrate possible configurations of multiple openings 56 in thebase pipe. These openings 56 can be positioned within the annular region43 portion of the base pipe, which, in this example, is the region 59that is between the region 57 for attaching the end 44 to the base pipe40, and the region 58 where the wire wraps 42 of the filter layer may bepositioned in the screen assembly 24. The screen assembly 24 can beconfigured at the surface to provide a desired flow rate and/or flowrestriction to fluid 30 flowing through the screen assembly 24. Aportion of the openings 56 can have VFR systems 25 installed in themwith the remaining openings (if there are any) plugged with plug 54.Additionally, the VFR systems 25 can be configured in various paralleland series arrangement to further tailor the desired flow rate and/orflow restriction. The arrows for fluid flow 32 and 38 show possible flowpaths the fluid 30 may take with various configurations. It should beunderstood that many configurations of the VFR systems 25 can be used inkeeping with the principles of this disclosure.

FIGS. 5A-12 illustrate various embodiments of the VFR system 25 that canbe utilized for variable flow resistance applications, such as screenassemblies 24, with each feature in each of the embodiments useable ineach of the other embodiments in combination with or in replacement ofvarious other features. FIG. 5A shows a VFR system 25 with an axis 60 ofa body 68 of the VFR system 25. Fluid 30 enters the chamber 50 throughinlet 80 as fluid flow 33. If the fluid is a desired fluid, thenrotational flow 35 about axis 60 is reduced and a backpressure appliedto the fluid flow 33 is also reduced, thereby allowing increased fluidflow 34 to exit the chamber 50 via the outlet 82. If an undesired fluid(such as gas or water, when hydrocarbon liquid are being produced)enters the chamber 50 through inlet 80 as fluid flow 33, then rotationalflow 35 is increased in the chamber 50, thereby increasing backpressureapplied to the fluid flow 33 and reducing fluid flow through the VFRsystem 25.

In some embodiments, the location of the fluid inlet 80 can be such thatrotational motion is induced in the fluid 30 as it enters the chamber50. For example, the chamber 50 and fluid inlet 80 can be configuredsuch that fluid 30 entering the chamber 50 is introduced along a curvedsidewall (e.g. 76, 77 in some embodiments) of the chamber 50, which canset the fluid 30 into rotational motion within the chamber. Furthermore,there are no limitations regarding the separation of the fluid inlet 80and the fluid outlet 82 from one another. Generally, at least somedegree of separation can be maintained between the fluid inlet 80 andthe fluid outlet 82 so that an undesired fluid does not enter the fluidoutlet 82 without first undergoing rotational motion, but this is notrequired.

FIG. 5A shows an inlet 80, and outlet 82, and a conical-shaped chamber50. The chamber can include a cylindrical-shaped interior surface 77 andfrusto-conically-shaped interior surface 76 for inducing rotational flow35 of the fluid 30 as it flows through the VFR system 25. The rotationalfluid flow 35 generally rotates about an axis 60 that can be a centralaxis 60 of the VFR system 25, as well as a central axis 62 of thechamber 50. Please note that it is not a requirement for the axis 60 andthe axis 62 to be aligned as seen in FIG. 5A. These axes 60, 62 can beoffset (i.e. spaced apart, but parallel) and/or angled relative to eachother (see FIG. 9). The rotational fluid flow 35 can be increased ordecreased depending upon the physical characteristics of the fluid 30flowing though the VFR system 25, as described previously.

For purposes of discussion, please refer to FIGS. 13A and 13B which showa partial cross-sectional top view of the VFR system in FIG. 5A. FIG.13A illustrates how the rotational fluid flow 35 can be affected when adesired fluid is flowing through the VFR system 25. When a desired fluid(e.g. oil in oil production) enters the chamber 50 through the inlet 80,the inlet 80 directs the fluid flow 33 away from the axis 60 and towardthe surfaces 76, 77. The inlet 80 can be angled as shown in the FIGS.13A and 13B, which can be somewhere between and including tangential tothe interior surfaces 76, 77 and slightly directed away from the axis 60when the fluid 30 enters the chamber 50 via fluid flow 33, therebydirecting the fluid flow 33 into rotational fluid flow 35. With desiredfluid, the rotational flow 35 can be minimized. Additionally,counter-rotational flow 35 (called “eddy currents”) can be induced inthe flow of the desired fluid through the chamber 50, which tends tofurther reduce the rotational flow 35, thereby reducing travel time ofthe desirable fluid in the chamber 50 and increasing a flow rate throughthe VFR system 25 of the desired fluid.

FIG. 13B illustrates how the rotational fluid flow 35 can be affectedwhen an undesired fluid is flowing through the VFR system 25. When theundesired fluid (e.g. water and/or gas in oil production) enters thechamber 50 through the inlet 80, the inlet 80 directs the fluid flow 33away from the axis 60 and toward the surfaces 76, 77. Because of thephysical properties of the undesired fluid, rotational fluid flow 35 isincreased in the chamber 50 and travel time of the fluid through thechamber 50 is increased, thereby decreasing a flow rate of the undesiredfluid through the VFR system 25.

Referring to FIGS. 5B and 5C, these embodiments of the VFR system 25 arevery similar to FIG. 5A, except that the outlet 82 is configureddifferently for FIGS. 5B and 5C. FIG. 5C has an outlet with an axis 64that is angled with angle A from the axis 60. This angle can be tailoredto accommodate various exit angles of the fluid 30 as it exits thechamber 50 as fluid flow 34. FIG. 5C has an outlet with a curved exitpath through which fluid 30 can exit the chamber 50 as fluid flow 34. Itshould be understood that the exit path from the chamber 50 for thefluid 30 can have many different configurations, as well as havingmultiple outlets 82.

The VFR system 25 in FIG. 6 is very similar to the VFR system 25 in FIG.5A, except that the outlet 82 allows fluid 30 to exit from the VFRsystem 25 through a bottom surface 70 of the VFR system 25. FIGS. 7A and7B illustrate how the rotational fluid flow 35 can be affected whenflowing through the VFR system 25 of FIG. 6.

FIG. 7A illustrates how the rotational fluid flow 35 can be affectedwhen an undesired fluid is flowing through the VFR system 25 of FIG. 6.When the undesired fluid (e.g. water and/or gas in oil production)enters the chamber 50 through the inlet 80, rotational fluid flow 35 canbe induced. Because of the physical properties of the undesired fluid,rotational fluid flow 35 is increased in the chamber 50 and travel timeof the fluid 30 through the chamber 50 is increased, thereby decreasinga flow rate of the undesired fluid through the VFR system 25.

FIG. 7B illustrates how the rotational fluid flow 35 can be affectedwhen a desired fluid is flowing through the VFR system 25 of FIG. 6.When the desired fluid (e.g. oil in oil production) enters the chamber50 through the inlet 80, the rotational flow 35 can be minimized andtravel time of the fluid 30 through the chamber 50 is decreased, therebyincreasing a flow rate of the desired fluid through the VFR system 25.

FIG. 8 illustrates an embodiment of the VFR system 25 that has twoinlets 80 to the chamber 50. The two inlets 80 are shown opposite eachother relative to the chamber 50, but they can be otherwise oriented, ifdesired. For example, the two inlets 80 can be positioned at spacedapart locations other than the 180 degree position shown in FIG. 8.Also, more than two inlets 80 can be used in keeping with the principlesof this disclosure.

For purposes of discussion, please refer to FIGS. 14A and 14B which showa partial cross-sectional top view of the VFR system 25 in FIG. 8. FIG.14A illustrates how the rotational fluid flow 35 can be affected when adesired fluid is flowing through the VFR system 25 of FIG. 8. Verysimilar to the discussion regarding fluid flow through the VFR system 25of FIG. 5A, when a desired fluid (e.g. oil in oil production) enters thechamber 50 through the inlets 80, the inlets 80 can direct the fluidflow 33 away from the axis 60 and toward the surfaces 76, 77. The inlets80 can be angled as shown in the FIGS. 14A and 14B, which can besomewhere between and including tangential to the interior surfaces 76,77 and slightly directed away from the axis 60 when the fluid 30 entersthe chamber 50 via fluid flow 33, thereby directing the fluid flow 33into rotational fluid flow 35. With desired fluid, the rotational flow35 can be minimized. Additionally, counter-rotational flow 35 (called“eddy currents”) can be induced in the desired fluid flow through thechamber 50, which tends to further reduce the rotational flow 35,thereby reducing travel time of the desirable fluid in the chamber 50and increasing a flow rate through the VFR system 25 of the desiredfluid.

FIG. 14B illustrates how the rotational fluid flow 35 can be affectedwhen an undesired fluid is flowing through the VFR system 25 in FIG. 8.When the undesired fluid (e.g. water and/or gas in oil production)enters the chamber 50 through the inlet 80, the inlet 80 directs thefluid flow 33 away from the axis 60 and toward the surfaces 76, 77.Because of the physical properties of the undesired fluid, rotationalfluid flow 35 is increased in the chamber 50 and travel time of thefluid through the chamber 50 is increased, thereby decreasing a flowrate of the undesired fluid through the VFR system 25.

The VFR system 25 in FIG. 9 is very similar to the previous embodimentsof the VFR system 25, except that the chamber 50 is tilted in referenceto the central axis 60 of the VFR system 25. The inlet 80 can beperpendicular to either the axis 60 or axis 62, as well as any angleother than these, as long as the angle tends to induce rotational flowof the fluid.

The VFR system 25 in FIG. 10 is very similar in operation to theprevious embodiments of the VFR system 25, except that the chamber 50has an irregular shape, where the irregular shape is not necessarilyconically or cylindrically shaped, but rather otherwise curved asindicated by the profile in FIG. 10, as well as possibly having ininterior surface 76, 77 that can undulate circumferentially around thechamber 50. The outlet 82 can also be non-circular in shape, such as anoval or polygon shape (including a triangle, rectangle, etc.). Theoutlet 82 may also be angled relative to the axis 60 as illustrated inFIG. 10. An additional feature shown in FIG. 10 is the protrusion 90which can extend from the top interior surface 78 into the chamber 50 tofurther induce or otherwise urge the fluid flow 33, which can bereceived through the inlet 80, into rotational flow 35 in the chamber 50The inlet 80 can be perpendicular to the axis 60, as well as any otherangle. It should be understood that the protrusion 90 can be used in anyof the embodiments of the VFR system 25.

The VFR system 25 in FIG. 11A is very similar to the VFR system 25 inFIG. 6, except that the internal surfaces 76, 77 can be made with afinish that is not smooth. For example, these surfaces can be channeled,splined, recessed, a wavy non-uniform finish and/or otherwise configuredto create more turbulent flow in the chamber 50 when rotational fluidflow 35 is experienced by the fluid 30 in the chamber 50. Additionally,various protrusions 90 can be formed that extend from the top interiorsurface 78 of the chamber 50. FIG. 11A shows only one protrusion 90extending from the surface 78, however, multiple protrusions 90 can beformed on the surface. The protrusion 90 can also be positioned otherthan in the center of the VFR system 25, such as in FIG. 11B which has aprotrusion with an axis 66 that is spaced away from the axis 60 of theVFR system 25 by a distance C. The protrusion 90 can also form acircumferentially extending protrusion that can at least partiallyencircle the axis 60. The protrusion 90 can have several other shapes,such as a frusto-conical shape as seen in FIG. 11C, as well asprotrusions 90 with cross-sections that are rectangular, triangular,and/or other polygonal shapes.

Other surfaces, such as surfaces 76, 77, 79 can also include theseprotrusions 90 extending into the fluid flow of the chamber 50 and/oroutlet 82. Furthermore, the VFR system 25 can also include recessedfeatures 92, shown in FIG. 11A as recesses with rectangular ortriangular cross-sections. These recesses can extend circumferentiallyaround the axis 60 for at least a partial distance and multiple suchrecesses can be used.

FIG. 12 shows yet another possible embodiment of the VFR system 25. Thisconfiguration includes an inlet 80, an outlet 82, and a chamber 50 thatcan resemble two cone shaped regions joined together at the narrowportion of the cone shapes. This provides a longer flow path forundesired fluids, since the rotation induced by the upper region of thechamber 50 can be supported and maintained in the lower region of thechamber 50. The cross-section of any of the embodiments of the VFRsystem 25 can be circular, as in the case of a cone-shaped chamber, orrectangular, such as is the case of pyramid-shaped chamber (a square isa rectangle with equal length sides). The chamber cross-section can alsobe any other polygon shape as desired for controlling fluid flow, whichcan include a triangular cross-section. The cross-section can also beirregularly shaped, as described above regarding FIG. 10.

FIGS. 15A and 15B each show a partial cross-sectional top view of a VFRsystem 25 that has a rectangular cross-section (e.g. pyramid shaped).FIG. 15A illustrates how the rotational fluid flow 35 can be affectedwhen a desired fluid is flowing through the VFR system 25. When adesired fluid (e.g. oil in oil production) enters the chamber 50 throughthe inlet 80, the inlet 80 can direct the fluid flow 33 away from theaxis 60 and toward the surfaces 76, 77. The inlet 80 can be angled asshown in the FIGS. 15A and 15B, which can be somewhere between andincluding tangential to the interior surfaces 76, 77 and slightlydirected away from the axis 60 when the fluid 30 enters the chamber 50via fluid flow 33, thereby directing the fluid flow 33 into rotationalfluid flow 35. With desired fluid, the rotational flow 35 can beminimized. Additionally, counter-rotational flow 35 (called “eddycurrents”) can be induced in the desired fluid flow through the chamber50, which tends to further reduce the rotational flow 35, therebyreducing travel time of the desirable fluid in the chamber 50 andincreasing a flow rate through the VFR system 25 of the desired fluid.

FIG. 15B illustrates how the rotational fluid flow 35 can be affectedwhen an undesired fluid is flowing through the VFR system 25. When theundesired fluid (e.g. water and/or gas in oil production) enters thechamber 50 through the inlet 80, the inlet 80 directs the fluid flow 33away from the axis 60 and toward the surfaces 76, 77. Because of thephysical properties of the undesired fluid, rotational fluid flow 35 isincreased in the chamber 50 and travel time of the fluid through thechamber 50 is increased, thereby decreasing a flow rate of the undesiredfluid through the VFR system 25.

Therefore, a system is provided for autonomous flow control of a fluid30 using one or more variable flow resistance systems 25, where the VFRsystem 25 can include a body 68 with a chamber 50 configured to inducerotational flow in a fluid 30 that flows through the chamber 50. Thechamber 50 can include an inlet 80 through which the fluid 30 enters thechamber 50 and an outlet 82 from which the fluid 30 exits the chamber50. The chamber 50 can have a cross-sectional area that decreases alonga central axis 62 of the chamber 50 toward the outlet 82, where thecross-sectional area is perpendicular to a central axis 62. A resistanceto fluid flow through the chamber 50 can vary based on a physicalproperty of the fluid 30.

Other embodiments of the system may also include a well screen assembly24 with a base pipe 40, a filter layer 53, a drainage layer 52, firstand second ends 44, 46 of the assembly 24 secured to the base pipe 40 atopposite ends of the filter layer 53, an annular space 43 within thefirst end 44, and multiple openings 56 formed in a region 59 on the basepipe 40 defined by the annular space 43. One or more VFR systems 25 canbe installed in the multiple openings 56 to tailor the fluid flowresistance and/or flow rate through the well screen assembly 24.

For any of the foregoing embodiments, the claimed system may include anyone of the following elements, alone or in combination with each other:

The inlet 80 can be angled away from the central axis 62 of the chamber50, where the angle of the inlet 80 can induce the rotational flow 35 inthe fluid 30. The angle of the inlet 80 can range from being slightlyoff-center from the central axis 62 of the chamber 50 up to beingtangential to an inner surface 77, 76 of the chamber 50.

The physical property of the fluid 30 that can vary the flow resistancecan be viscosity, velocity, and/or density. The resistance to the fluidflow through the chamber 50 can be increased when an undesired fluid 30flows through the chamber 50 and decreased when a desired fluid 30 flowsthrough the chamber 50. The desired fluid 30 can be a hydrocarbon liquidwith the undesired fluid 30 being a gas and/or water. Alternatively, thedesired fluid 30 can be a gas and the undesired fluid 30 can be ahydrocarbon liquid and/or water.

A cross-sectional area of the chamber 50 can be an oval, a circle, asquare, a rectangle, a polygon, or an irregular shape. As used herein,an “irregular shape” refers to a shape that is not an oval, a circle, asquare, a rectangle, or a polygon. For example, the irregular shape canbe an undulating surface, a wavy surface, a jagged surface, and/or arandom surface encircling the central axis 62 of the chamber 50. Thechamber 50 can be tapered along the central axis 62 toward the outlet82. For example, the taper can be due to a chamber 50 with an invertedcone shape, where the inlet 80 is at a base of the cone and the outlet82 is at a peak of the cone. It should be understood that other shapes(such as pyramid, polygon, etc. as mentioned in this disclosure) canalso be tapered from the inlet 80 to the outlet 82. As used herein,“tapered chamber” refers to a chamber 50 with a varied cross-sectionalarea along the center axis 62 of the chamber 50 with the largestcross-sectional area being proximate the inlet 80 of the chamber 50 andthe smallest cross-sectional area being proximate the outlet 82 of thechamber 50. The slope of the chamber surface 76 with the taper does nothave to be a linear surface, just that on average, the cross-sectionalarea of the chamber 50 decreases along the central axis 62 toward theoutlet 82.

An inner surface 76, 77, 79 of the chamber 50 can be smooth, grooved,splined, channeled, circumferentially spaced apart recesses,circumferentially spaced apart irregular protrusions, and/or coated withan abrasive material.

A top surface 78 (i.e. top inner surface 78) of the chamber 50 caninclude a protrusion 90 positioned at the central axis 62, one or morechannels positioned circumferentially about the central axis 62, and/orone or more recesses positioned circumferentially about the central axis62. The protrusion 90 can be positioned at the central axis 62 (oroffset from the center axis 62 of the chamber 50), and the protrusion 90can be a hemi-spherical, a pyramid, a conical, a frusto-conical, acylindrical, a polygonal, or a tapered polygonal shape.

The central axis 62 of the chamber 50 can be angled relative to acentral axis 60 of the body 68. Fluid 30 flowing through the outlet 82can exit the body 68 through a bottom surface 70 of the body 68 or aside surface 74 of the body 68. A central axis 64 of the outlet 82 canbe angled relative to the central axis 62 of the chamber 50.

The well screen assembly 24 can also include multiple VFR systems 25installed in multiple openings 56 in the annular region 59 of the basepipe 40 of the well screen assembly 24. These VFR systems 25 can beconfigured for parallel and/or series fluid flow through the well screenassembly 24. Series fluid flow occurs when the outlet 82 of one VFRsystem 25 is coupled to the inlet 80 of another VFR system 25, so fluidflow through a series connection of VFR systems 25 in the well screenassembly 24 would travel through each VFR system 25 coupled in series.Parallel fluid flow occurs when each VFR system 25 connected in parallelreceives fluid 30 through its inlet 80 and outputs fluid 30 from itsoutlet 82 simultaneously, with the fluid 30 flowing through one of theparalleled VFR systems 25 does not flow through the other paralleled VFRsystems 25. Therefore, series connections can increase a fluid flowrestriction through the well screen assembly 24, while parallelconnections can increase fluid flow rate through the well screenassembly 24.

A quantity of the multiple VFR systems 25 installed in the openings 56of the well screen assembly 24 in the annular region 59 of the end 44can be determined by calculating the number of VFR systems 25 needed toproduce a desired flow restriction and/or flow rate for flowing thefluid 30 through the well screen assembly 24.

Although various embodiments have been shown and described, thedisclosure is not limited to such embodiments and will be understood toinclude all modifications and variations as would be apparent to oneskilled in the art. Therefore, it should be understood that thedisclosure is not intended to be limited to the particular formsdisclosed; rather, the intention is to cover all modifications,equivalents, and alternatives falling within the spirit and scope of thedisclosure as defined by the appended claims.

1. A variable flow resistance system providing autonomous flow control of a fluid, the system comprising: a body; a chamber in the body, with the chamber configured to induce rotational flow in a fluid that flows through the chamber; an inlet through which the fluid enters the chamber; an outlet from which the fluid exits the chamber; the chamber having a cross-sectional area that decreases along a central axis of the chamber toward the outlet, wherein the cross-sectional area is perpendicular to a central axis; and a resistance to fluid flow through the chamber varies based on a physical property of the fluid.
 2. The system of claim 1, wherein the inlet is angled away from the central axis of the chamber and the angle induces the rotational flow in the fluid.
 3. The system of claim 1, wherein the physical property is at least one of viscosity, velocity, and density.
 4. The system of claim 1, wherein the resistance to the fluid flow through the chamber is increased when an undesired fluid flows through the chamber and is decreased when a desired fluid flows through the chamber.
 5. The system of claim 4, wherein the desired fluid is hydrocarbon liquid and the undesired fluid is gas and/or water.
 6. The system of claim 4, wherein the desired fluid is gas and the undesired fluid is hydrocarbon liquid and/or water.
 7. The system of claim 1, wherein the cross-sectional area of the chamber is one of an oval, a circle, a square, a rectangle, a polygon, and an irregular shape.
 8. The system of claim 7, wherein the chamber is tapered from the inlet to the outlet.
 9. The system of claim 7, wherein an inner surface of the chamber is at least one of smooth, grooved, splined, channeled, circumferentially spaced apart recesses, circumferentially spaced apart protrusions, and coated with an abrasive material.
 10. The system of claim 7, wherein a top surface of the chamber includes at least one of a protrusion positioned at the central axis, one or more channels positioned circumferentially about the central axis, and one or more recesses positioned circumferentially about the central axis.
 11. The system of claim 1, wherein a top surface of the chamber includes a protrusion positioned at the central axis, and wherein the protrusion is one of a hemi-spherical, a pyramid, a conical, a frusto-conical, a cylindrical, a polygonal, and a tapered polygonal shape.
 12. The system of claim 1, wherein the central axis of the chamber is angled relative to a central axis of the body.
 13. The system of claim 1, wherein fluid flowing through the outlet exits the body through a bottom surface of the body.
 14. The system of claim 1, wherein fluid flowing through the outlet exits the body through a side surface of the body.
 15. The system of claim 1, wherein a central axis of the outlet is angled relative to the central axis of the chamber.
 16. A well screen assembly comprising: a base pipe; a filter layer; a drainage layer; first and second ends, with the first and second ends secured to the base pipe at opposite ends of the filter layer; an annular space within the first end; multiple openings formed in a region on the base pipe defined by the annular space; and a variable flow resistance system installed in at least one of the openings, the variable flow resistance system comprising: a body; a chamber in the body, with the chamber configured to induce rotational flow in a fluid that flows through the chamber; an inlet through which the fluid enters the chamber; an outlet from which the fluid exits the chamber; the chamber having a cross-sectional area that decreases along a central axis of the chamber toward the outlet, wherein the cross-sectional area is perpendicular to the central axis; and a resistance to fluid flow through the chamber varies based on a physical property of the fluid.
 17. The assembly of claim 16, wherein the variable flow resistance system includes multiple variable flow resistance systems installed in respective ones of the multiple openings, with the multiple variable flow resistance systems configured for parallel and/or series fluid flow through the well screen assembly.
 18. The assembly of claim 17, wherein a quantity of the multiple variable flow resistance systems installed in the respective ones of the multiple openings is determined by a desired flow restriction and/or flow rate for flowing the fluid through the well screen assembly.
 19. The assembly of claim 16, wherein the inlet to the chamber is angled away from the central axis of the chamber and the angle induces the rotational flow of the fluid in the chamber.
 20. The assembly of claim 16, wherein the physical property is at least one of viscosity, velocity, and density.
 21. The assembly of claim 16, wherein a cross-sectional area of the chamber is one of an oval, a circle, a square, a rectangle, a polygon, and an irregular shape.
 22. The assembly of claim 21, wherein the chamber is tapered from the inlet to the outlet.
 23. The assembly of claim 21, wherein an inner surface of the chamber is at least one of smooth, grooved, splined, channeled, circumferentially spaced apart recesses, circumferentially spaced apart protrusions, and coated with an abrasive material.
 24. The assembly of claim 21, wherein a top surface of the chamber includes at least one of a protrusion positioned at the central axis, one or more channels positioned circumferentially about the central axis, and one or more recesses positioned circumferentially about the central axis.
 25. The assembly of claim 16, wherein a top surface of the chamber includes a protrusion positioned at the central axis, and wherein the protrusion is one of a hemi-spherical, a pyramid, a conical, a frusto-conical, a cylindrical, a polygonal, and a tapered polygonal shape.
 26. The assembly of claim 16, wherein fluid flowing through the outlet exits the body through a bottom surface of the body.
 27. The assembly of claim 16, wherein fluid flowing through the outlet exits the body through a side surface of the body. 